Pump



1,624,209 April 12 1927' G. A. BROWN ET AL PUMP Filed Nov. 11. 1920 Patented Apr. 12, 1927.

UNITED STATES PATENT OFFICE.

GEORGE A. BROWN AND FRANK G. DENNISON, OF BRIDCEPORT. CONNECTICUT, .AS-

SIGNORS TO BRIDGEPORT BRASS COMPANY, OF BRIDGEPORT, CONNECTICUT.

PUMP.

Application filed November 11, 1920. Serial No. 423,358.

This invention relates to pumps and more particularly to air pumps of the type used for the inflation of the tires of automobiles, bicycles and the like. These pumps ordinarily comprise a cylinder and a piston operating therein, the piston usually being provided with a flexible washer or pump bucket which makes a close contact with the cylinder wall. The flexible washer or pump bucket is usually made of leather or of a fibrous material, and it has been found that this washer sometimes becomes dried out and type above described, it is understood that the invention is not limited to the exact form shown, but may be applied to pumps for any gases or liquids which require the piston to fit tightly within the cylinder.

One object of the invention is to improve the efficiency of this class of pumps.

A further object of the invention is to provide the pump bucket usually employed in this classof pumps with a member which will tend to keep the bucket in close contact with the cylinder wallduring the operative stroke of the pump.

A'still further object of this invention is to provide a fluid pump of the character described with an improved pump bucket, which will be expanded by the c'olumn of fluid upon the operative side of the same into contact with the cylinder walls, but which may be permitted to recede from the chamber walls during the return stroke of the pump so that the fluid upon which the pump- -is working may be permitted to. pass the same.

Another object of the invention to provide a resilient means toforcea bucket expander into expanding relation with; the pump bucket.

To these and other ends the invention resides in the novel features and combinations which our improvements are applied, the

Fig. 4 is a perspective view ofone of the pistons showing applied thereto. I Fig,- 5 is a perspective view of the expand.- ing member; and

Fig. 6 is a perspective detail view of the resilient spider, which serves to force the expanding member into operative position relative to the pump bucket.

The fluid pump, which we have chosen to illustrate a preferred form of our invention, may consist of the two cylinders 11 and 12, which are connected at their lower ends by a base 13 to which the lower ends of the cylinders may be secured in any preferred way. A channel 14 in the base member 13 connects the two cylinders. The upper ends of the pump bucket expander conventional way, the drawings showing 4 them to be provided with the caps 15 and tached to the bar 19 by which the pump may be operated.

the cylinders may be closed in' any usual and The downward stroke of the} piston 17, as

shown in Figs. 1 and 2, is the operative stroke of the same, but the reverse arrangement may, of course, be provided andin such a case the upstroke would be the operative one. The piston 18 is arranged so that its operative stroke is the upward one and the fluid in the pump shown is delivered from the upper end of the cylinder 12 through the tube 20. The parts so far de- "scribed'are of old and usual form, and arev merely used to show the application of the. improved parts, which will now be described. The piston rod 17, as shown in F ig." 2, is provided with a piston which comprises two plates or disks 21 and 23, between which the leather packing cup or pump. bucket 22 is clamped. As shown, this packing cup is flexible and is cup-shaped to provide a skirt I portion which will, when the piston is moving in one direction, be urged to an expanded position by the fluid. below the same into close contact with the cylinder walls. The packing cup or pumpbucket 22 is formed of .not operate at all, or will operate with a very low efficiency. To overcome this disadvantage, we have provided an expanding member 24, which, as shown, is of cup-shape somewhat similar to the shape of the pack ing cup itself. This member is provided with a central perforation 25 through which the piston loosely extends, so that the packing cup may be freely mounted upon the piston rod below the piston. The piston rod 1s provided with a nut 26 upon its lower end to limit the downward movement of the expanding member on the same. The expanding member may be left loose upon the piston rod, so that it will be forced into expanding relation with the packing'cup by the fluid which will be on the operative side of the piston, or may be spring-pressed into engagement with the packing cup by a resilient spiderlike member 27, which is mounted upon the rod 17 with its legs extending upwardly into engagement with the expanding member 24. It is seen that this will retain the member 24 in expanding relation with the packing cup 22 at all times. The legs of the spider 27 are, however, of resilient material, so that some movement of the expanding member may be permitted.

In order to operatively position the parts of the piston and the expanding members upon the piston rod 17, the latter is preferably provided with a shoulder 28 against which the upper surface of the plate 21 rests. The end of the piston rod is reduced in size below thisshoulder and is threaded as at 30 for the reception of the nut 26. A spacing collar 3lis slipped upon the reduced end of the rod to hold the two plates 21 and 23 and the leather washer 22 firmly against the shoulder 28. The perforation 25 in the expanding member is sufficiently large so that this member slipsloosely over the collar 31. The spider 27 is slipped on the rod below the collar, and a washer 32 is placed between the spider and the nut 26, which when tightened into position will secure the parts firmly in place, while at the same time will permit movement of the expanding member longitudinally upon the collar 31. A similar arrangement may be provided upon the other piston rod 1.8, except that the parts will, of course, be placed in reversed position upon the rod, as shown in Fig.- 1. The precise means by which these members are secured upon the piston rods may, of course, be varied without departing from the spirit of the invention. 1

The conical expanding member 24, as

shown in Figs. 3, 4 and 5, is relieved at certain points about its periphery, as shown at 29. These relieved portions are providedv so panding member toward the pump bucket, it is advisable to provide these relieved portions so that the passage of fluid around the pump bucket will be permitted upon the return stroke of the piston.

It is seen that although the operative stroke of the smaller piston is the upstroke of the same, the shape of the pump bucket is the same as that in the other cylinder and the expanding member will have the same action. As has been stated, the spring member may be dispensed with and the expanding member may be merely loosely mounted upon the piston rod 18. It is seen that in the t 7 case of the cylinder 12 that the weight of the expanding member will tend to keep it in engagement with the pump bucket, although the resilient spider member 27 may be used, if desired. As shown in Fig. 1 of the drawings, the spider member 27 is provided on both pistons.

The operation of our device is as follows:

When the handle 19 is drawn upwardly, the fluid in the cylinder 12 will be carried upwardly by the piston and forced out through the tube 20. The air in the cylinder 11 will at this time be permitted to ass down around the piston and will fill this cylinder and the cylinder 12. When the handle 19 is given its downward stroke the reverse action will take place. The fluid within the cylinder 11 will be forced down and around into the cylinder 12 and above the piston in the latter cylinder. It is seen that upon the downward stroke of the piston in the cylinder 11 and the upward stroke of the piston in the cylinder 12, that the flexible pump buck ets will be expanded into contact with the cylinder walls by the expanding members 24. so that the fluid will not be allowed to pass around the pistons, but will be driven before them. Upon the return strokes of the two pistons, the fluid will around the same either through the relieved portions of the periphery of the expanding member, or by the moving of the ex anding member out of contact with the flexib e pump bucket. The expanding member 24 is preferably formed of very light sheet metal or fibre, so that it will maintain its shapeunder the conditions of operation within the cylinders.

loo

be permitted to pass' While we have shown and described a preferred embodiment of our invention, it is to be understood that the same is not limited in all respects to the exact details shown, but is capable of many modifications and variations which .Wlll fall within the spirit of the invention and within the scope of the appended claims.

What we claim is:

1. In a fluid pump, a cylinder, a piston operating therein, said piston being provided with a exible pump packingcup, and a spring pressed member in engagement with said packing cup to expand the same, and having PI'OVlSlOIl, independent of the spring, for permitting the passage of air around the cup on the return stroke of the piston.

2. An expanding member generally frusto conical in shape adapted to engage a fluid pump packing cup at spaced points to expand the same and having a continuous side wall.

3. In a pump, a cup-shaped member for expanding the packing cup against the cylin-.

der wall, said member having a continuous side wall relieved at certain points in its periphery to permit the passage of air-therearound.

4. In a fluid pump, a cylinder, a piston operating therein having a flexible pump bucket and a one piece spring pressed member to expand said bucket into contact with the cylinder to prevent the fluid passing therebetween during an operative stroke thereof, said means permitting such passage on the return stroke.

5. In a fluid pump, a cylinder, a piston, operating therein having a flexible pump bucket and means to engage said bucket to expand it into close contact with the cylinder wall during an operative stroke thereof, said means being shaped to allow the bucket to recede from the cylinder wallupon the return stroke without moving from its engaging position.

6. In a fluid pump, a cylinder, a piston operating thereon having a flexible pump bucket, and an expanding member associated with said bucket to force the same into contact with the cylinder wall at certain points during an operative stroke of the piston, said member being relieved at certain points to allow passage of the fluid between the bucket and cylinder wall during a return stroke.

7. In a fluid pumip, a piston rod a iston thereon havin a exible pump uc et, a

tapered expan ing member associated with said bucket and a spider to urge said expanding member to operative position relative to said bucket.

8. In a fluid pump, a piston rod, a piston thereon having a flexible pump bucket, an expanding member associated with said bucket and a resilient spider member to urge said expanding member to operative position relative to said bucket.

9. In a fluid pump, a cylinder, a piston rod therein provided with a piston havin a pump bucket, a one-piece expanding mem er loosely mounted on the piston rod to urge the bucket into tight engagement with the cylinder wall upon the operative stroke of the piston, said expanding member having an irregularly shaped periphery to permit the passage of air around the ,bucketon the return stroke, and sprin means to urge said member toward said buc et.

10. In a fluid pump provided with a cylinder, a piston rod operating therein having a piston provided with a cup shaped pump bucket, a tapered expander and a spider member to engage said expander to force the pump bucket into contact with the cylinder walls upon an operative stroke thereof.

11. In a fluid pump, a piston, a packing cup operatively mounted thereon, and a spring-pressed member to expand said packing cup, said member being formed to permit the collapse of said packing cup at spaced points in the periphery thereof upon the return stroke of the piston for the purpose described.

12. In a fluid pump, a piston, a packing cup mounted thereon, an expanding member loosely mounted on the piston, and spring means to urge said expanding member into operative engagement with the packing cup,

said expanding member having a continuous side wall but being relieved at spaced points in the periphery thereof to permit the collapse of the packing cup upon a return stroke of the piston and allow the fluid to pass therearound.

In witness whereof, we have hereunto set our hands on the 8th day of November, 1920.

' a GEORGE A. BROWN.

FRANK G. DENNISON. 

